Apparatus for removing sand cores from hollow drill rod by sand blast



Oct. 13, 1925. 1,557,131

P. A. E. ARMSTRONG APPARATUS FOR REMOVING SAND GOHES FROM HOLLOW DRILL ROD BY SAND BLAST Original Filed Dec. 13, 1919 HICi-H PRESSURE HICTH eessurza 2 anoento'c Patented Oct. 13, 1925.

um'run STATES PATENT PERCY A. E. ARMSTRONG, OF LOUDONVILLE, NEW YORK, ASSIGNOR T L'UDLUlllI STEEL COMPANY, OF WATERVLIET, NEW YORK, A' CORPORATION OF NEW JERSEY.

APPARATUS-FOR REMOVING GORES FRO'M HOLLOW DRILL ROD BY SAND BLAST.

Original application filed December 13,1919, Serial No. 344,738. Divided and this application filed October 28, 1920. Serial No. 420,186.

To all whom it may concern-.-

Be it known that I, PERcY A. E. ARM- STRONG, a subject of the King of Great Britain, and a resident of Loudonville, county of 6 Albany, State of New York, have invented certain new and useful Improvements in Apparatus for Removing Sand Cores from Hollow Drill Rod by Sand Blast, of which the following is a specification.

My invention relates to apparatus for removing sand cores from tubular bodies, such as hollow drill rod, by means of a sand blast. The term sand core is used herein as a convenient expression to cover cores of .1 various refractory materials, such as sand,

dead burned magnesite, talc powder, lime,

zirconia and the like. The present application is a division of my prior copending application Serial #344,738, filed December In the manufacture of tubular bodies such as hollow drill rod by hot working a hollow 'ingot with a sand core therein for elongation and reduction of cross section of the ingot an core, as'by rolling, the core in the resulting elongated rod of reduced cross section is extremely compact and diflicult to remove.

Heretofore, so far as I am aware, such removal has been accomplished by drilling or by air blast. Drilling operations are troublesome, slow, and expensive; and while compressed air may be used for this purpose,

vthe difiiculty with the use of theair blast,

not laden with abrasive particles, resides in the comparatively weak original attack of the air upon the resistant core. VVhen the air or other gaseous fluid is laden with abrasive particles, making what is known as a sand blast, this difficulty is avoided, the initial attack is highly powerful and efiective, and the material of the core is rapidly brokon .down and removed.

The accompanying drawings illustrate forms of apparatus embodying my invention.

In the drawings Fig. 1 is a transverse sec-v tion ofan apparatus in which the dbris of the core is discharged through a pipe and the abrasive laden air enters around the pipe and between it and the bore walls. .Fig. 2 is an enlarged sectional diagrammatical view showing the operation of the apparatus of Fig. 1, and Fig. 3 is a view similar to Fig. 2,

but showing the abrasive laden air oonducted 1n through the pipe and the discharge taking place through the annular space be tween the outside of the pipe and the walls of the bore.

Reference numeral 10 designates the tubular body, suchas a drill rod, and 11 the sand core which is tobe removed from the bore 12. The hollow head 13 is supported in any suitable manner, and the tube 10 is removably clamped therein by suitable means, such as the cam 14. The pipe 15 extends into head 13 througha packing device as indicated at 16, in line with the bore 12; and the pipe 15 is introduced into bore 12and advanced therein as the core material is removed. Various means may be used for advancing the pipe 15.

Air, under pressure is admitted to head 13, as by pipel17, provided with means such as flap valve 18 to prevent sand from getting into the air pipe. -'Two sources of air, one at higher pressure than the other are preferably provided, as, for example, pipe 19, controlled by valve 20 may carry compressed air at suitable pressure for sand blast work, 80 and pipe 21, also connected to pipe 17, and controlled by valve .22 may serve to supply compressed air at a .higher pressure. I Instead'of air other suitable gaseous fluids maybe used.

Means are provided .for supplying abrasive particles, as for example, fine sand, to the chamber 23 in head13. In the form shown, a relatively tall and narrow canister 24 is provided communicating with chamber 23 by passage 24, controlled by valve 25. The canister is preferably made tall to carry a sufficient quantity of abrasive, and narrow to avoid undue pressure on the head 26, which is preferably bolted in place, and provided with a plug 27 having a handle 28 for convenience in filling with sand from time to time. The pressures are preferablybal anced on opposite sides of valve 25, as by the by-pass pipe 29, controlled byvalve 29. A pipe 30, controlled byrvalve 81 is preferably led to about ,the top of canister 24, and serves At such timespipe 17 is protected from en-g try of sand, if the low pressure connectlon' should be open, by flap valve 18, and valve 29 may be closed.

lVhen the air laden with abrasive material 32 is conducted into tube around the outside of pipe 15, as shown by the arrows in Fig. 1, it is confined so as to exert its primary attack against the sand core in a. narrow annular region adjacent to the bore walls, as indicated at 33, Figs. 1 and 2. Dueto the presence of the abrasive particles the initial attack on the sand core in this region is highly efiective, andthe core material being loosened in such annular region and freed from the bore walls is rapidly broken up and 34 of pipe 15.

As the sand or'other abrasive material 32 may be quite finely divided, no difticulty is encountered in delivering same through the narrow annular] passage 35 "between p pe 15 and the walls 36 of bore 12, and the pipe 15, may be of comparatively large' diameter, leaving the bore 34 thereof sufficiently large for discharge of particles of comparatively large size, which may result from the effective breaking .up of core by the sand blast. 7

In the alternative apparatus of Fig. 3, the sand blast enters through the hm-e37 of pipe 38, is discharged centrally against the face of the core 11, as at- 39, and the dbris of the core, together with the sand and air of the sand blast, are discharged through the annular pipe 38. l

The preferred mode of applying the sand-blast, however, is as shown in Figs. 1 and 2, since the alternative mode of Fig. 3, while usable, requires a smaller pipe 38 in order to leave sufiicient room for discharge of core particles of even moderate size, and in the case of making hollow drill rod havinga completed bore of onlyabout of an inch diameter, it is desirable to be able to use a pipe of maximum siz: and ruggedness, also th are likely to be more or less irregular and rough, which also interferes with free outwardpassage of comparatively large particles around the pipe 38, whereaswith the form of Figs. 1 and 2 the particles .have a free outward passage through the smooth bore 34 of the relatively large diameter. Also th form of' Figs. 1 and 2 is better adapted for removal of hollow center cores, which break down rapidly when attacked by sand blast close up to the bore walls.

To make use of the apparatus the rod or tube containing the core to be removed is secured in place and the' air turned on,

.sufliciently to admitthe requisite amount a source of suction, narily this IS unnecrs'sary. discharged through the bore.-

passage 40 about walls of the drill rod bore can be opened and valve 29 closed for a short interval, which will usually be all that is necessary to free thes'and passage. If the discharge from the tube 10 should become clogged it may be freed by admitting the high pressure air 'by valve 22, valve 20 being preferably closed at such times. The discharge can be connected with if desired, though ordi- It is to beunderstood that the apparatus shown is only for illustration and for affording an understanding of the invention, andthat changes and modifications may be resorted to within .the scope-of my claims. v

I claim:

1. Apparatus for removing a sand core from the bore of a tubular body, comprising a member containing a mixing chamber, means for supplying sand to said chamber, means for supplying gaseous fluid to said chamber under pressure, an outlet passage from said chamber being provided in a walltthereof, means for holding the cored tubular body with the cored part in register with said passage, and an outlet pipe for core material'discharged from the said tubular body, said pipe extending through said chamber and passage and adapted to project into the bore of the tubular body. i 2. In apparatus for removing hardened cores from tubular bodies, such as hollow drill rod and the like, a member having a mixing chamber provided therein, and said chamber having an outlet adapted to be brought. into communication with the end 'munication therewith, a by-pass-pipe communicating with the air said' chamber and with the space over the sand in the reservoir for balancing the pressure upon opposite sides of the sand, and high pressure air supplying means for communicating with the mixing chamber or with the sand reservoir above the sand therein, whereby any In testimony that I claimthe fore going I hereto set my hand, this 26th day of October, 1920.

PERCY A. E. ARMSTRONG.

clogged sand may be blown out and the obstruction removed.

supply pip for I 

